Battery
Disclosed herein is a battery that includes a chargeable/dischargeable battery cell and an outer case that houses the battery cell. The outer case having first and second top plates overlapping each other as viewed in a thickness direction thereof. The first top plate has a first convex part and a first concave part having mutually different heights in the thickness direction, the second top plate has a second convex part and a second concave part having mutually different heights in the thickness direction. The first convex part overlaps the second concave part as viewed in the thickness direction, and the second convex part overlaps the first concave part as viewed in the thickness direction.
Latest TDK CORPORATION Patents:
- Electromagnetic wave test device and electromagnetic wave test method
- Vibration device and electronic apparatus
- Power management device and power storage system
- Ferrite sintered magnet, ferrite particles, bonded magnet, and rotating electrical machine
- Electronic component embedded substrate and circuit module using the same
The present invention relates to a battery and, more particularly, to a battery having a structure in which a battery cell is housed in an outer case.
Description of Related ArtIn recent years, a battery such as a lithium-ion battery is widely used as a power supply for electric cars or hybrid cars. A lithium-ion battery for cars is required to have high safety and reliability, so that a structure in which a battery cell is housed in a sealed outer case is generally used as described in JP 2016-095930A.
A lithium-ion battery for cars sometimes has a structure in which a large number of battery cells are connected in parallel for achieving a large capacity. In this case, a battery cell positioned at a center part surrounded by other battery cells may become poor in heat radiation performance, making degradation or failure of battery cells likely to occur due to excessive heat.
SUMMARYIt is therefore an object of the present invention to provide a battery provided with an outer case having excellent heat radiation performance.
A battery according to the present invention includes a chargeable/dischargeable battery cell and an outer case that houses the battery cell. The outer case has first and second top plates overlapping each other as viewed in the thickness direction thereof. The first top plate has a first convex part and a first concave part having mutually different heights in the thickness direction, and the second top plate has a second convex part and a second concave part having mutually different heights in the thickness direction. The first convex part overlaps the second concave part as viewed in the thickness direction, and the second convex part overlaps the first concave part as viewed in the thickness direction.
According to the present invention, the top plate of the outer case has a concavo-convex shape, so that the surface area is increased to improve heat radiation performance and mechanical strength. Further, even when the plurality of batteries are stacked, interference between the convex parts is prevented, allowing the plurality of batteries to be densely stacked. In order to sufficiently improve heat radiation performance of the outer case, metal is preferably used as a material of the outer case.
In the present invention, the height of a step formed by the first convex part and first concave part in the thickness direction is preferably equal to the height of a step formed by the second convex part and second concave part in the thickness direction. With this configuration, when the plurality of batteries are stacked, they can be stacked further densely, and adjacent outer cases contact each other in a wide range, whereby heat radiation performance can be further improved.
In the present invention, it is preferable that the outer case seals the battery cell and that the space between the battery cell and each of the first and second convex parts in the thickness direction is larger than the space between the battery cell and each of the first and second concave parts in the thickness direction. With this configuration, a space is formed in a portion corresponding to the convex part, so that even when the battery cell is expanded due to an increase in the inner pressure or a reduction in the external atmospheric pressure, deformation of the outer case can be prevented.
As described above, in the battery according to the present invention, even in a configuration where the plurality of batteries are stacked, it is possible to prevent deformation of the outer case while ensuring high heat radiation performance.
The above features and advantages of the present invention will be more apparent from the following description of certain preferred embodiments taken in conjunction with the accompanying drawings, in which:
Preferred embodiments of the present invention will be explained below in detail with reference to the accompanying drawings.
First EmbodimentThe battery 10 according to the present embodiment may be a lithium-ion battery and includes an outer case 20, a positive electrode terminal 31, a negative electrode terminal 32 and a gas valve 40 as illustrated in
The outer case 20 has a substantially box-like shape having a z-direction thickness. A first top plate 21 and a second top plate 22 constituting the xy plane each have a concavo-convex shape. The top plates of the outer case 20 of the battery 10 according to the present embodiment each have such a concavo-convex shape, so that the surface area of the battery 10 is larger as compared with the case where the top plates each have a flat surface. As a result, not only heat radiation performance, but also mechanical strength is improved more than ever before. Although not especially limited, the side surface (xz plane and yz plane) does not have a concavo-convex shape. The positive electrode terminal 31, negative electrode terminal 32, and gas valve 40 are formed in the xz plane.
In the present embodiment, two convex parts 21A and two concave parts 21B are formed in the first top plate 21 so as to extend in the y-direction, and two convex parts 22A and two concave parts 22B are formed in the second top plate 22 so as to extend in the y-direction. The convex part refers to a portion protruding in the z-direction, and the concave part refers to a portion recessed in the z-direction. Accordingly, the convex part and the concave part have mutually different heights in the z-direction. As illustrated in
As illustrated in
As illustrated in
Thus, in the present embodiment, even when the battery cell 50 is expanded due to an increase in the inner pressure or a reduction in the external atmospheric pressure, the space 60 thus formed inside the outer case 20 acts as a margin, thereby making it possible to prevent deformation of the outer case 20.
As illustrated in
In the example illustrated in
As described above, in the battery 10 according to the present embodiment, the top plates 21 and 22 of the outer case 20 each have a concavo-convex shape, so that the surface area is increased to improve heat radiation performance and mechanical strength. Further, the concavo-convex shape of each of the top plates 21 and 22 is reflected in the inner wall of the outer case 20, so that the space 60 is formed inside the outer case 20, and the thus formed space 60 can be utilized as a margin for expansion of the battery cell 50. In addition, the concavo-convex shape formed in the first top plate 21 and the concavo-convex shape formed in the second top plate 22 are complementary as viewed in the z-direction, whereby interference between the convex parts can be prevented when the plurality of batteries 10 are stacked in the z-direction. Further, the width W1 of each of the convex parts 21A and 22A is substantially equal to or slightly smaller than the width W2 of each of the concave parts 21B and 22B, thus facilitating the positioning of the plurality of batteries 10 to be stacked.
Second EmbodimentAs illustrated in
As illustrated in
As illustrated in
As exemplified in the present embodiment, even in a configuration where the convex parts 21A and 22A and concave parts 21B and 22B extend in the x-direction, the same effects as those obtained in the battery 10 according to the first embodiment can be obtained as long as the concavo-convex shape formed in the first top plate 21 and the concavo-convex shape formed in the second top plate 22 are complementary as viewed in the z-direction. In the present embodiment, a width W3 of each of the convex parts 21A and 22A in the y-direction may be substantially equal to or slightly or sufficiently smaller than a width W4 of each of the concave parts 21B and 22B in the y-direction. When the width W3 is sufficiently smaller than the width W4, a cooling medium such as air or coolant can be circulated in the x-direction.
Fourth EmbodimentAs illustrated in
As exemplified in the present embodiment, the convex parts 21A and 22A and concave parts 21B and 22B need not extend in one direction, and the same effects as those obtained in the battery 10 according to the first embodiment can be obtained as long as the concavo-convex shape formed in the first top plate 21 and the concavo-convex shape formed in the second top plate 22 are complementary as viewed in the z-direction.
While the preferred embodiments of the present invention have been described, the present invention is not limited thereto. Thus, various modifications may be made without departing from the gist of the invention, and all of the modifications thereof are included in the scope of the present invention.
For example, although the present invention is applied to a lithium-ion battery in the above embodiments, the application target of the present invention is not limited to the lithium-ion battery and includes batteries of other types.
Claims
1. A battery comprising:
- first and second chargeable/dischargeable battery cells; and
- first and second outer cases that house the first and second battery cells, respectively, the first outer case having first and second top plates overlapping each other as viewed in a thickness direction thereof, and the second outer case having third and fourth top plates overlapping each other as viewed in the thickness direction,
- wherein the first top plate has a first convex part and a first concave part having mutually different heights in the thickness direction,
- wherein the second top plate has a second convex part and a second concave part having mutually different heights in the thickness direction,
- wherein the third top plate has a third convex part and a third concave part having mutually different heights in the thickness direction,
- wherein the fourth top plate has a fourth convex part and a fourth concave part having mutually different heights in the thickness direction,
- wherein the first convex part, the second concave part, the third convex part, and the fourth concave part overlap one another as viewed in the thickness direction,
- wherein the first concave part, the second convex part, the third concave part, and the fourth convex part overlap one another as viewed in the thickness direction,
- wherein the first convex part has a first side surface extending in the thickness direction,
- wherein the fourth convex part has a second side surface extending in the thickness direction, and
- wherein the first and second side surfaces are in contact with each other.
2. The battery as claimed in claim 1, wherein a height of a step formed by the first convex part and first concave part in the thickness direction is substantially equal to a height of a step formed by the fourth convex part and fourth concave part in the thickness direction.
3. The battery as claimed in claim 1,
- wherein the first and second outer cases seal the first and second battery cells, respectively,
- wherein a space between the first battery cell and each of the first and second convex parts in the thickness direction is larger than a space between the first battery cell and each of the first and second concave parts in the thickness direction, and
- wherein a space between the second battery cell and each of the third and fourth convex parts in the thickness direction is larger than a space between the second battery cell and each of the third and fourth concave parts in the thickness direction.
4. The battery as claimed in claim 1, wherein each of the first and second outer cases comprises metal.
5. The battery as claimed in claim 1,
- wherein the first top plate further has a fifth convex part,
- wherein the fourth top plate further has a fifth concave part overlapping the fifth convex part as viewed in the thickness direction,
- wherein the fifth convex part has a third side surface extending in the thickness direction,
- wherein the fourth convex part further has a fourth side surface extending in the thickness direction, and
- wherein the third and fourth side surfaces are in contact with each other.
6. The battery as claimed in claim 5, wherein the fourth convex part is arranged between the first and fifth convex parts.
7. The battery as claimed in claim 5,
- wherein the first top plate further has a sixth concave part,
- wherein the fourth top plate further has a sixth convex part overlapping the sixth convex part as viewed in the thickness direction,
- wherein the sixth convex part has a fifth side surface extending in the thickness direction, wherein the first convex part further has a sixth side surface extending in the thickness direction, and
- wherein the fifth and sixth side surfaces are in contact with each other.
8. The battery as claimed in claim 7, wherein the first convex part is arranged between the fourth and sixth convex parts.
20040142238 | July 22, 2004 | Asahina |
20130309546 | November 21, 2013 | Park |
20140113172 | April 24, 2014 | Enghardt |
2016-095930 | May 2016 | JP |
Type: Grant
Filed: Jan 19, 2018
Date of Patent: Oct 27, 2020
Patent Publication Number: 20180212207
Assignee: TDK CORPORATION (Tokyo)
Inventors: Takayuki Mino (Tokyo), Mikio Tsuruoka (Tokyo)
Primary Examiner: Ladan Mohaddes
Application Number: 15/875,209
International Classification: H01M 2/02 (20060101); H01M 10/0525 (20100101); H01M 10/613 (20140101); H01M 10/6557 (20140101); H01M 10/625 (20140101); H01M 2/10 (20060101); H01M 10/647 (20140101); H01M 10/6561 (20140101); H01M 10/052 (20100101);